Duolingo

Version: 5.93.3

Google Play: click

Mod features:
1. Unlocked Plus Subscription
2. Fixed Facebook auth
3. Unlocked debug menu

Mendeleeva Table Pro

Version: 3.1

Google Play: click

Mod features:
1. Disabled license check
2. Monochrome icon

Spotify

Version: 8.8.22.510

Google Play: click

Mod features:
1. Full unlock best quality(include Spotify's test Hi-Fi)
2. Unlock A/B manager for toggles and debug menu
3. Unlock local playing
4. Unblock all country-lock music
5. Unlock all server-side features
6. Monochrome icon
7. Full redisign to material you

Unique feature:
look at the calendar date, guys :)

Duolingo

Version: 5.97.2

Google Play: click

Mod features:
1. Unlocked Plus Subscription
2. Fixed Facebook auth
3. Unlocked debug menu

Busuu

Version: 30.1.1(600093)

Google play: click

Mod features:
1. Unlocked plus subscription

Some features are server side

Monefy

Version: 1.16.0

Google play: click

Mod features:
1. Unlocked pro

Citra

Version: bed6a4f12

Google play: click

Mod features:
1. Unlocked donate features

Anixart

Version: 8.1.3

Google play: No available

Mod features:
1. Unlocked Sponsor subscription
2. Deleted metrics
3. Deleted ads
4. Added monochrome(themed) icon (thanks @coldroman for icon)

VK Music

Version: 6.1.136

Google play: click

Mod features:
1. Unlocked Premium subscription
2. little optimization
3. Deleted ads
4. Added monochrome icon